2PSK误码率程序及仿真图

clearall;closeall;clcframe=10000;t=0:pi/180:2*pi;source_code=randint(1,500);SNR=0:0.25:10;carrier1=sin(2*pi*t);carrier2=sin(2*pi*t+pi);Carrier=[carrier1carrier2];snr=10.^(SNR./10);forloop=1:length(source_code)ifsource_code(loop)==1modulated_signal(loop,:)=carrier1;elsemodulated_signal(loop,:)=carrier2;endendModulated=reshape(modulated_signal',1,loop*length(carrier1));Modulated_Information=2*source_code-1;foriteration=1:length(SNR)error=0;fori=1:frameadd_noise=awgn(Modulated_Information,SNR(iteration));foraddress=1:length(add_noise)ifadd_noise(address)0demodulated(address)=1;elsedemodulated(address)=0;endifdemodulated(address)~=source_code(address)error=error+1;endendendPe(iteration)=error/frame/length(source_code);Pe_theor=(erfc(sqrt(snr))).*(1-0.5*erfc(sqrt(snr)));endfigure(1)semilogy(SNR,Pe_theor,'Marker','o','Color','r');gridon;holdon;semilogy(SNR,Pe,'Marker','*','Color','b')%axis([snrdB_minsnrdB_max0.00011]);xlabel('信噪比');ylabel('误码率');title('BPSK信号最佳接收误码率曲线');legend('理论值','实际值');图4-2BPSK信号误码率的仿真图function[enc_comp]=cm_dpske(E,M,mapping,sequence);k=log2(M);N=length(sequence);reminder=rem(N,k);if(reminder~=0),fori=N+1:N+k-reminder,sequence(i)=0;end;N=N+k-reminde;endtheta=0;fori=1:k:N,index=0;forj=i:i+k-1,index=2*index+sequence(j);endindex=index+1;theta=mod(2*pi*mapping(index)/M+theta,2*pi);enc_comp((i+k-1)/k,1)=sqrt(E)*cos(theta);enc_comp((i+k-1)/k,2)=sqrt(E)*sin(theta);end==============================================function[p]=cm_sm35(SNRindB)N=2000;E=1;snr=10^(SNRindB/10);sgma=sqrt(E/(4*snr));fori=1:2*N;temp=rand;if(temp0.5),dsource(i)=0;elsedsource(i)=1;endendmapping=[0132];M=4;[diff_enc_output]=cm_dpske(E,M,mapping,dsource);fori=1:N,[gsrv1,gsrv2]=gngauss(sgma);r(i,:)=diff_enc_output(i,:)+[gsrv1,gsrv2];endprev_theta=0;numoferr=0;fori=1:N,theta=angle(r(i,1)+j*r(i,2));delta_theta=mod(theta-prev_theta,2*pi);if((delta_thetapi/4)|(delta_theta7*pi/4)),decis=[00];elseif(delta_theta3*pi/4),decis=[01];elseif(delta_theta5*pi/4),decis=[11];elsedecis=[10];endprev_theta=theta;if((decis(1)~=dsource(2*i-1))|(decis(2)~=dsource(2*i))),numoferr=numoferr+1;end;end;p=numoferr/N;=======================================echoonSNRindB1=0:2:12;SNRindB2=0:0.1:12;fori=1:length(SNRindB1),[pe]=cm_sm35(SNRindB1(i));smld_bit_err_prb(i)=pe;echooff;end;echoon;fori=1:length(SNRindB2),SNR=exp(SNRindB2(i)*log(10)/10);theo_err_prb(i)=Qfunct(sqrt(2*SNR));echooff;end;semilogy(SNRindB2,theo_err_prb);holdonsemilogy(SNRindB1,smld_bit_err_prb,'*');